Erica irregularis is fairly easy to propagate by seed. Collect the seed just as it starts to fall naturally in August, or 3 months after flowering, and sow in autumn. As E. irregularis is a re-seeder and adapted to germinating after fire, it would be advantageous to give the seeds a smoke treatment in a smoking tent, or to pre-soak the seeds in an aqueous smoke extract or seed primer for 24 hours before sowing.

Use a well-drained sowing medium such as 1 part river sand and 1 part sifted composted bark, and firm down the surface of the medium. To prevent damping-off often associated with overcrowding, sow the seeds thinly and evenly, by mixing them with fine sand prior to sowing. A thin layer of propagation medium can be sieved over the seeds. Water the seeds with a very fine hose to prevent dislodging them and place containers under cover in a shade house, until the seeds germinate. The seed trays should be kept moist, but not wet.

Take cuttings from healthy, disease-free plants about 2 months after flowering. At this stage, the plants would have grown shoots that are semi-hard. Nodal cuttings can be used, although heel-cuttings are most suitable. Carefully remove the leaves on the lower third, dip the cuttings into a rooting hormone and insert into a cutting medium of one part milled bark and one part polystyrene. Place the cuttings in a greenhouse with intermittent mist, or in an open air mist spraying unit. Erica cuttings require good air circulation. When the cuttings have rooted well, they can be planted into pots in the same growing medium as for seedlings.

When the seedlings are 10 mm tall and the cuttings are well established, they can be placed in an open, but lightly shaded area. Ericas require good air circulation at all times. When seedlings are 20–50 mm in height, prick them out and plant into pots or plant bags. Erica’s have very sensitive hair-like roots situated close to the surface of the medium and disturbance of these roots should be minimal. Like the propagation medium, the potting soil should be well-drained and slightly acidic. A sandy loam with 50% humus, a pH of between 5 and 5.5, and low levels of phosphate, is recommended for most ericas. Three parts sand, 2 parts leaf mould/bark and 1 part soil can be used. Place a mulch consisting of untreated woodchips, pine needles or stones around the plant on the surface of the potting medium to protect the delicate roots, keep them moist and cool, and to suppress weed growth. Once the plants are established, they can be moved out into the open. Water the plants well every second or third day, preferably in the mornings to prevent fungal infections from developing on the leaves. Fertilize with organic liquid fertilizers such as those derived from seaweeds, or very carefully with a controlled-release granular fertilizer that is low in phosphate.

This beautiful erica would do well in protected, sandy, coastal gardens, planted together with other coastal fynbos species such as blombos (Metalasia muricata), gonna (Passerina corymbosa), restios and bietou (Osteospermum moniliferum).